Turkish President Recep Tayyip Erdogan will arrive in the Iranian capital on Friday to discuss the latest developments on war-torn Syria, according to presidential sources.

Iranian President Hassan Rouhani will host the trilateral summit in Tehran, with a focus on Syria.

Erdogan and Russian President Vladimir Putin will attend the talks where a range of issues would be discussed, including securing territorial integrity in Syria, preventing human rights violations, and developments in Idlib.

Erdogan will also hold bilateral talks with Putin and Rouhani.

Senior officials of the three countries will also gather to work on a joint declaration which will be released after the summit.

Turkey, Russia and Iran are guarantor countries of de-escalation zones in Syria.

The first tripartite summit was held in Russia’s Black Sea resort of Sochi on Nov. 22, 2017 to discuss progress made in the Astana peace talks and changes in de-escalation zones across Syria.

The second trilateral meeting was hosted by Erdogan in April in the Turkish capital Ankara.